CODEWITHSUNDEEP
typescriptzod
Lzok
Lzok

Reputation: 156

Is there a way to have an array of objects with some of them literals?

I'm thinking about the following validation with zod and I have no clue on how to do it (or if it's possible with zod). I want an array of objects, all with the same shape, with some of them with literal props, I need these always present in the array.

Example: I need always in the array the objects those with name required1 and required2, and then other objects optionals following the same shape.

[
    {
      name: z.literal('required1'),
      otherprop: z.number()
    },
    {
      name: z.literal('required2'),
      otherprop: z.number()
    },
    // I want to include one or more of the following too (optionals).
    {
      name: z.string(),
      otherprop: z.number()
    },
]

This other example needs to throw because required2 is missing

[
    {
      name: z.literal('required1'),
      otherprop: z.number()
    },
    // I want to include one or more of the following too.
    {
      name: z.string(),
      otherprop: z.number()
    },
]

Any clue?

Upvotes: 3

Views: 24752

Answers (1)

Lzok
Lzok

Reputation: 156

There is no way to solve the problem from just the typing system. I solved the issue using the refine method from Zod. I will post two versions, one simpler with refine and other more complex with superRefine.

Base code

const elementSchema = z.object({
  name: z.string(),
  otherprop: z.number(),
})
type Element = z.infer<typeof elementSchema>;

// In my real code, here I have a function that returns the array of required names for the case.
const names = ['required1', 'required2'];

function refineNames(elements: Element[]): boolean {
       return names.every((el: string) => elements.some(x => x.name === el));
}

Simple way using just refine

z.array(elementSchema).refine(
  (elements) => refineNames(elements),
  { message: `There are missing names. Required names are ${names.join(', ')}`, }
);

Complex way using superRefine. But we can compare also for duplicate entries.

function hasDuplicates(elements: Element[]): boolean {
    const names = elements.map(e => e.name);

    return names.length !== new Set(names).size;
}

z.array(elementSchema).superRefine((elements, ctx) => {
        if (refineNames(elements)) {
            ctx.addIssue({
                code: z.ZodIssueCode.custom,
                message: `There are missing names. Required names are ${names.join(', ')}`,
            });
        }

        if (hasDuplicates(elements)) {
            ctx.addIssue({
                code: z.ZodIssueCode.custom,
                message: 'No duplicated name allowed.',
            });
        }
    }),

References:

Upvotes: 5

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